JP3204399B2 - Polyester fiber and fabric using the same - Google Patents

Abstract

A polyester resin composition is disclosed, comprising poly(trimethylene terephthalate) in a proportion of 90 wt% or more, wherein the resin composition has an intrinsic viscosity of from 0.4 to 2 and contains a phosphorus compound corresponding to from 10 to 250 ppm in terms of the amount of phosphorus element, a cyclic dimer in an amount of not exceeding 3 wt% and a bis(3-hydroxypropyl)ether in an amount of 2 wt% or less. This polyester resin composition has excellent spinning stability and high melt stability and is used for the production of a poly(trimethylene terephthalate)-based fiber having excellent whiteness and high tenacity.

Description

Description: TECHNICAL FIELD The present invention relates to a polyester fiber which is excellent in whiteness and stability and easily develops high strength, and a fabric using the same. The present invention relates to a polyester fiber having excellent whiteness and strength produced using a polytrimethylene terephthalate resin in which a decrease in molecular weight in a state is largely suppressed, and a fabric using the same.

BACKGROUND ART Polytrimethylene terephthalate fibers have properties similar to nylon fibers such as soft texture derived from low elasticity, excellent elastic recovery, and easy dyeing, and wash and wear properties, dimensional stability, yellowing resistance and the like. It is an epoch-making fiber having properties similar to polyethylene terephthalate fiber, and is being applied to clothing, carpets and the like by utilizing its characteristics.

Polytrimethylene terephthalate can be polymerized in the same manner as polyethylene terephthalate and polybutylene terephthalate, which have similar chemical structures. That is, first, a lower alcohol diester of terephthalic acid such as terephthalic acid or dimethyl terephthalate and trimethylene glycol (or 1,3-propanediol) are used without a catalyst or with a metal carboxylate or titanium alcohol. The transesterification reaction represented by the formula (1) is carried out in the presence of a catalyst such as an oxide or an organic acid while heating, and then the polycondensation reaction represented by the formula (2) is carried out using titanium alkoxide, antimony oxide or the like. The reaction can be carried out under reduced pressure using the above catalyst.

ROOCφCOOR + HOCH ₂ CH ₂ CH ₂ OH → HOCH ₂ CH ₂ CH ₂ OOCφCOOCH ₂ CH ₂ CH ₂ OH + ROH Formula (1) (R: -H or -CH3, φ: benzene ring with para bond) HOCH ₂ CH ₂ CH ₂ OOCφCOOCH ₂ CH ₂ CH ₂ OH → (OCH ₂ CH ₂ CH ₂ OOCφCO) _n (2) However, the polymerization of polytrimethylene terephthalate is technically different from polyethylene terephthalate and polybutylene terephthalate, and has various technical difficulties. Accompanied by
There are still unresolved issues. That is, this technical problem can be generally summarized into three problems of whiteness, spinning stability and melt stability.

The problem relating to whiteness is that the obtained fiber or fabric is also colored because the polymer is colored yellow in the polymerization stage, and the performance of the product is impaired. In particular, innerwear, pantyhose, sportswear, outerwear, and the like are promising fields in which the soft texture of polytrimethylene terephthalate fiber, excellent elastic recovery, and easy care properties can be utilized. In order to develop products in these fields, the whiteness of the fibers is sufficiently high, and therefore, it is necessary that all colors, from light to dark, be developed neatly.
However, polytrimethylene terephthalate is liable to be colored in the polymerization stage, and even if a fiber or a fabric is produced using a polymer having poor whiteness and coloring, the color development of the dyed fiber product is lost sharply, and the commercial value is significantly impaired. Will be.

The problem with spinning stability is that the polymer contains many impurities which adversely affect spinning stability. That is, in the polymerization process of polytrimethylene terephthalate, the content of cyclic dimers, other cyclic and linear oligomers, etc. is large, and they are deposited around the spinneret during spinning, and the frequency of yarn breakage and cleaning of the spinneret (wiping cycle) Problem). In particular, the amount of the cyclic dimer is large, which is the main cause of the above problem.

Problems with melt stability include poor thermal stability of the melted polymer, lower molecular weight, and coloration of the polymer. In particular, the fact that the molecular weight tends to decrease means that the molecular weight decreases at the stage of melt spinning even if the molecular weight is increased at the polymer stage. When such a phenomenon occurs, it becomes difficult to increase the strength of the fiber, which adversely affects the basic performance of the product such as a decrease in tear strength or burst strength of the fabric product.

If these three technical problems can be completely solved, a polytrimethylene terephthalate fiber having excellent whiteness and easy to produce industrially and having sufficient strength can be obtained. A satisfactory polytrimethylene terephthalate and a fiber using the same have not been known.

As a method for improving the whiteness and spinnability of polytrimethylene terephthalate, several known techniques are known.

For example, Japanese Patent Application Laid-Open No. Hei 5-262628 discloses a technique in which a tin catalyst is used as a polymerization catalyst to improve whiteness. However, according to the study of the present inventors, the polymerization rate was very high when the tin catalyst was used, but the whiteness was worse than when the titanium alkoxide was used as the catalyst. In addition, although zinc acetate is used as the transesterification catalyst and a tin catalyst is used as the polycondensation catalyst, when only melt polymerization is performed without performing solid-phase polymerization in such a combination,
Since the amount of cyclic dimer exceeds 3% by weight, spinning stability is not good. In the examples of this reference, a maximum of 500 ppm of tridecyl phosphate is allowed to coexist during the polymerization. The coexistence of a compound having such a long chain has a disadvantage that bubbles are generated at the dyeing stage and stain spots are easily caused. Further, when a tin catalyst or tridecyl phosphate is used, the strength of the obtained fiber is low, and it has been difficult to develop a strength of 3.5 g / d or more.

In order to improve whiteness, it has been proposed to use a titanium catalyst as a transesterification catalyst and an antimony catalyst as a polycondensation catalyst (Chemical Fiber International, Vol. 45, pp. 263-264, 1996).
Year). This document also mentions the generation of by-products, and shows that polytrimethylene terephthalate may contain oligomers in an amount of 3% or more in some cases, and that these impurities are problematic in the spinning and dyeing processes. I have. However, according to the investigations of the present inventors, the use of an antimony catalyst slows down the polymerization rate, which increases the exposure time of the polymer at a high temperature, but rather reduces the whiteness. Further, this method does not specifically suggest reduction of the amount of oligomers or improvement of the melt stability of the polymer.

JP-A-8-311177 discloses that polytrimethylene terephthalate obtained by an ordinary method is reduced under reduced pressure to 190 to reduce white powder generated on and around the spinneret surface in the spinning step and to suppress yarn breakage. By performing solid-state polymerization at about 200 ° C, the intrinsic viscosity is 0.9 or more, and b value (index for judging the yellowness of chips)
It is described that a polytrimethylene terephthalate resin having a polymer content of 10 or less and an oligomer content of 1% by weight or less can be obtained. Referring to the examples described in this publication, terephthalic acid and phosphorus compounds and cobalt compounds were not used.
1,3-propanediol is transesterified without a catalyst,
Thereafter, tetrabutyl titanate (titanium butoxide) was added to prepare a prepolymer having an intrinsic viscosity of 0.70, followed by solid phase polymerization to obtain a polymer having an intrinsic viscosity of 1.02. However, when such a polymer is melted, it undergoes rapid thermal decomposition, and the molecular weight decreases. Therefore, a polymer having a high degree of polymerization obtained by this method does not become a fiber having sufficient strength due to a decrease in viscosity occurring in the spinning step.

International application (WO) 9823662 discloses polytrimethylene terephthalate end-capped with a hindered phenol moiety and a method for producing the same in order to reduce the amount of acrolein generated when heated in air. I have. In this known example, terephthalic acid, trimethylene glycol, an ester-forming monofunctional dicarboxylic acid having a hindered phenol moiety is subjected to transesterification under high pressure in the presence of an oriphenyl phosphite-based stabilizer,
Thereafter, a polymer is obtained by a polycondensation reaction. However, the triphenyl phosphite-based stabilizer used here partially sublimates in the course of the polycondensation reaction performed under a high-temperature vacuum, and the amount of phosphorus element in the obtained polymer is significantly reduced. Therefore, the obtained polymer has low melt stability, and it is difficult to obtain a fiber having high strength. Further, this publication has no suggestion about the problem that the melt stability of the polymer gives to the fiber strength. This publication discloses that the polymer contains bis (3-hydroxypropyl) ether in an amount of about 4 mol% (more than 2% by weight). However, such a polymer has remarkable heat resistance and light resistance. Because of its low value, it cannot be used in the production of clothing fibers. Furthermore, since this known technique is a technique in which the transesterification reaction is performed under high pressure, large-scale equipment that can withstand high pressure is industrially required, which is economically disadvantageous.

JP-A-9-195142 discloses that terephthalic acid and 1,3-
After transesterification of propanediol, a fiber using polytrimethylene terephthalate having an intrinsic viscosity of 0.92 obtained through polycondensation at 250 ° C. is disclosed.Examples include:
An example is described in which a fiber having a strength of 5.2 g / d and an elongation of 41% is used as a core yarn of a composite yarn. However, it is difficult to industrially stably produce fibers having a practical level of strength by overcoming the problems of polymer whiteness and melt stability using this known technique. This is because even if a fiber having such strength can be obtained, the polycondensation temperature is 25%.
Because the temperature is as low as 0 ° C., this polymer contains 3% by weight or more of the cyclic dimer, so that fluff and yarn breakage increase, resulting in a yarn having low homogeneity.

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a polytrimethylene terephthalate fiber having high whiteness and excellent strength.

Another object of the present invention is to provide a polyester fiber having excellent whiteness and strength using polytrimethylene terephthalate having excellent spinning stability. Still another object of the present invention is to provide a polytrimethylene terephthalate fiber excellent in strength that can be dyed vividly.

The present inventors have conducted various studies to obtain a method for producing polytrimethylene terephthalate which is excellent in whiteness itself, has little coloring in the melt-spinning stage, and can easily obtain high-strength fibers. By optimizing the polymerization conditions below, we succeeded in reducing the amount of impurities that adversely affect whiteness, spinning stability, and melt stability, and produce fibers such as melt-spun polymers obtained. The object of the present invention has been achieved by studying the details of the process conditions.

That is, the present invention is a polyester fiber satisfying the following conditions (1) to (5) and having an intrinsic viscosity of 0.4 to 2.

(1) 90% by weight or more is composed of polytrimethylene terephthalate. (2) A phosphorus compound corresponding to an amount of 10 to 250 ppm as a phosphorus element is contained. (3) A cyclic dimer of 3% by weight or less is contained. ) 2% by weight or less of bis (3-hydroxypropyl)
It contains ether and is copolymerized with polytrimethylene terephthalate. (5) The birefringence is 0.03 or more.

The polyester fiber of the present invention has a weight of 90% based on the weight of the fiber.
The polyester fiber composed of polytrimethylene terephthalate accounts for at least% by weight.

Here, polytrimethylene terephthalate is a polyester containing terephthalic acid as an acid component and trimethylene glycol (also referred to as 1,3-propanediol) as a diol component. This polytrimethylene terephthalate is
Other copolymer components may be contained at 10% by weight or less based on the weight of the fiber. As such a copolymer component, 5-
Sodium sulfoisophthalic acid, 5-potassium sulfoisophthalic acid, 4-sodium sulfo-2,6-naphthalenedicarboxylic acid, 3,5-dicarboxylic acid benzenesulfonic acid tetramethylphosphonium salt, 3,5-dicarboxylic acid benzenesulfonic acid tetrabutyl salt Phosphonium salt, 3,5-dicarboxylic acid benzenesulfonic acid tributylmethylphosphonium salt, 2,6-dicarboxylic acid naphthalene-4-sulfonic acid tetrabutylphosphonium salt, 2,6-dicarboxylic acid naphthalene-4-sulfonic acid tetramethylphosphonium salt , 3,5-dicarboxylic acid benzenesulfonic acid ammonium salt, 1,2-butanediol, 1,3-butanediol,
4-butanediol, neopentyl glycol, 1,5-pentamethylene glycol, 1,6-hexamethylene glycol, heptamethylene glycol, octamethylene glycol, decamethylene glycol, dodecamethylene glycol, 1,4-cyclohexanediol, 3-cyclohexanediol, 1,2-cyclohexanediol, 1,4-
Cyclohexane dimethanol, 1,3-cyclohexane dimethanol, 1,2-cyclohexane dimethanol, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid,
Heptane diacid, octane diacid, sebacic acid, dodecanedioic acid, 2-methylglutaric acid, 2-methyladipic acid, fumaric acid, maleic acid, itaconic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid acid,
Ester-forming monomers such as 1,2-cyclohexanedicarboxylic acid.

The intrinsic viscosity [η] (also called intrinsic viscosity) of the polyester fiber of the present invention needs to be 0.4 to 2.0. When the intrinsic viscosity is less than 0.4, the degree of polymerization of the polymer is too low, so that the strength of the obtained fiber becomes low and the spinnability becomes unstable. On the other hand, when the intrinsic viscosity exceeds 2.0, the melt viscosity is too high, so that the metering by the gear pump is not performed smoothly, and the spinnability is reduced due to poor discharge or the like. Further preferred intrinsic viscosity is 0.6 to 1.5, particularly preferably 0.6 to 1.5
1.4.

The polyester fiber of the present invention needs to contain a phosphorus compound corresponding to a phosphorus element amount of 10 to 250 ppm. From the polymerization of a monomer to a clothing product, melt polymerization, solid phase polymerization, chip drying at high temperature, melt spinning, scouring, heat setting, dyeing, etc. It exerts a very great effect on the prevention of discoloration and the improvement of the melt stability.

 Hereinafter, the phosphorus compound will be described in detail.

Polytrimethylene terephthalate is generally different from polyethylene terephthalate and polybutylene terephthalate, which are often used for clothing, especially melt polymerization,
Easy to color yellow when dried or melt spun. Phosphorus compounds are particularly effective in suppressing these colorings.

In addition, polytrimethylene terephthalate has a low melt stability, so the degree of polymerization tends to decrease during spinning. Even if spinning is performed using a raw material polymer or resin composition having a high intrinsic viscosity (hereinafter simply referred to as a raw material), There is a disadvantage that the strength of the fiber obtained by lowering the degree of polymerization is not so high. Phosphorus compounds also have a significant inhibitory effect on this decrease in viscosity.

As the phosphorus compound, an organic phosphorus compound is preferable. Particularly, as a phosphorus compound which has excellent effects of preventing coloration and melt stability and does not adversely affect the spinnability, O = P (OR ₁ ) (OR ₂ )
(OR ₃ ) or P (OR ₄ ) (OR ₅ ) (O
R ₆₎ there is a phosphite. Further, where R ₁ , R ₂ ,
R ₃ , R ₄ , R ₅ , and R ₆ are different or the same, and are preferably selected from a hydrogen atom, an organic group having 1 to 8 carbon atoms, an alkali metal, and an alkaline earth metal. R ₁ , R ₂ , R ₂ ,
When R ₄ , R ₅ , and R ₆ are organic groups having 9 or more carbon atoms, they have disadvantages such as bubbles appearing at the dyeing stage, and stain spots are easily caused, and the strength is not easily increased. Among these R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , and R ₆ , one of the alkoxy groups of the phosphorus compound is preferably a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. This is because these alkoxy groups are transesterified with trimethylene glycol to form a form that is easily dispersed in the polymer.
Such a phosphorus compound dispersed in a molecular order is particularly effective in preventing coloration and improving melt stability. In contrast,
R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ are all phenoxy groups or
The group in which a part or all of the hydrogen atoms on the benzene ring are substituted is difficult to transesterify with trimethylene glycol, so it is difficult to disperse in the molecular order, or because it has sublimability, during polymerization, It tends to be scattered outside the system, and the effects of preventing coloring and improving melt stability tend to be low. Therefore, it is preferable that at least one alkoxy group of the phosphorus compound is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an alkali metal, or an alkaline earth metal. As the phosphorus compound, P (OR ₄ ) (O
Since the phosphite of R ₅ ) (OR ₆ ) has a tendency to slightly inhibit polymerization, it is particularly preferable to use a phosphate of O ＝ P (OR ₁ ) (OR ₂ ) (OR ₃ ).

Preferred specific examples of these phosphorus compounds include phosphoric acid, trimethyl phosphate, triethyl phosphate, tripropyl phosphate, tributyl phosphate, tripentyl phosphate, trihexyl phosphate, triheptyl phosphate, trioctyl phosphate, dimethyl ethyl phosphate, and dimethyl phosphate. , Methyl phosphate, 3-hydroxypropyl phosphate, bis (3-hydroxypropyl) phosphate, tris (3-hydroxypropyl), phosphate, triphenyl phosphate, phosphorous acid, trimethyl phosphite, triethyl phosphite, triethyl phosphite, Tributyl phosphite, tripentyl phosphite, trihexyl phosphite, triheptyl phosphite, Riooctyl phosphite, dimethylethyl phosphite, dimethyl phosphite, methyl phosphite, 3-hydroxypropyl phosphite, bis (3-hydroxypropyl) phosphite, tris (3-hydroxypropyl) phosphite, triphenyl phosphite, Sodium phosphate, potassium phosphate, magnesium phosphate, calcium phosphate, dimethyl sodium phosphate, methyl disodium phosphate, and the like. Phosphorus is preferred from the viewpoint of excellent coloring prevention, melt stability, and low ability to inhibit polymerization. Acids, trimethyl phosphate, triethyl phosphate, tripropyl phosphate are particularly preferred.

The amount of the phosphorus compound contained in the fiber can be represented by the weight fraction of the phosphorus element contained in the fiber, and its range needs to be 10 to 250 ppm. If it is less than 10 ppm, the effect of preventing coloring and suppressing viscosity decrease is not sufficiently exhibited,
If the content exceeds 250 ppm, although these effects are sufficiently obtained, the polymerization catalyst is partially deactivated, so that melt polymerization or solid-state polymerization hardly proceeds. The preferred weight fraction of elemental phosphorus is 35-150 ppm, more preferably 50-120 ppm.

Although details will be described later, in the polymerization of polytrimethylene terephthalate, a metal catalyst such as titanium alkoxide such as titanium butoxide and titanium isopropoxide and antimony trioxide is used as a polycondensation catalyst. As the kind of the metal element in the metal compound used as the polycondensation catalyst, titanium, tin, and antimony are used because of their high activity. The phosphorus compound used in the present invention may react with these polycondensation catalysts to slightly lengthen the polymerization time. Therefore, in order to suppress the polymerization time from becoming long and to prevent the coloring and improve the melt stability, the ratio of the number of moles of the phosphorus element of the phosphorus compound to the number of moles of the metal element used as the polycondensation catalyst is determined. Is preferably set to 0.4 to 3, particularly preferably 0.55 to 2.

The polyester fiber of the present invention particularly preferably uses a cobalt compound in combination with a phosphorus compound, and the combined use has a synergistic effect of significantly reducing melt polymerization, drying and coloring during melt spinning. Examples of the cobalt compound include cobalt acetate, cobalt formate, cobalt carbonate, cobalt acetylacetonate, cobalt sulfate, cobalt chloride, cobalt bromide, cobalt hydroxide, cobalt nitrate, cobalt carbonate, and the like. It may be a hydrate.
Among these cobalt compounds, particularly preferably, from the viewpoint of excellent coloring prevention effect, cobalt acetate, cobalt formate, cobalt carbonate, cobalt acetylacetonate,
Cobalt sulfate.

The amount of the cobalt compound contained in the polyester fiber of the present invention can be represented by the weight fraction of the cobalt element contained in the fiber, and the range is 5 to 200 p.
It is preferably pm. If it is less than 5 ppm, the effect of preventing coloring is not sufficiently exhibited, and if it exceeds 200 ppm, the polymer is colored blue or blackish. Preferably, 10-15
0 ppm, more preferably 10 to 100 ppm.

The amount of the cyclic dimer contained in the polyester fiber of the present invention needs to be 3% by weight or less based on the weight of the fiber. The cyclic dimer described herein is a dimer in which trimethylene terephthalate units are connected in a ring. If this cyclic dimer is contained in the raw material in an amount of more than 3% by weight, it is deposited around the spinneret, at the oil agent nozzle and the guide at the time of spinning, and the wiping cycle is shortened. In order to stably perform long-time spinning for two weeks or more, it is desired that the cyclic dimer be maintained at 2% by weight or less, more preferably 1% by weight or less.

Bis (3-hydroxypropyl) ether (HOCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OH) contained in the polyester fiber of the present invention:
Hereinafter, abbreviated as BPE) needs to be 2% by weight or less based on the weight of the fiber. BPE is produced by trimerization of trimethylene glycol in the weight process as shown in the following formula, and is copolymerized as it is in polytrimethylene terephthalate. The amount of BPE produced depends on the polymerization catalyst, additives, polymerization temperature, polymerization time, and the amount of trimethylene glycol.

Since BPE copolymerized from 2 HOCH ₂ CH ₂ CH ₂ OH → HOCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OH has an ether unit, the thermal stability and light resistance of the fiber are reduced. When the amount of BPE exceeds 2% by weight, the melt stability of the raw material is remarkably reduced, and as a result, the fiber is colored and the strength of the fiber is easily reduced.

However, it was found that BPE did not only adversely affect the fibers, but the dyeability of the obtained fibers to disperse dyes was improved as the amount of BPE was increased. In particular, BPE
When the amount is in the range of 0.5 to 1% by weight, the fiber exhibits normal pressure dyeability without greatly decreasing the melt stability and light resistance. That the fiber exhibits normal pressure dyeability means that, for example, other fibers that deteriorate when dyed at a temperature of 100 ° C or more, for example,
Atmospheric pressure dyeing of a composite fabric mixed with polyurethane fiber, wool, silk, acetate fiber and the like becomes possible, and the usable area of polytrimethylene terephthalate fiber is expanded. This effect is remarkable when the dye concentration is about 4% owf or less. From these facts, the content of BPE contained in the polyester fiber of the present invention is preferably 1% by weight or less, more preferably 0.4 to 1% by weight.

In the polyester fiber of the present invention, if necessary, various additives, for example, a matting agent, a heat stabilizer, a defoaming agent, a tinting agent, a flame retardant, an antioxidant, an ultraviolet absorber, an infrared absorber, A nucleating agent, a brightening agent and the like may be copolymerized or mixed.

In particular, the polyester fiber of the present invention suppresses a decrease in viscosity at the time of melt spinning, and before drying or heat treatment before spinning, produces by-products of low molecular weight products generated by thermal decomposition of acrolein or allyl alcohol having a strong pungent odor. In order to suppress this, it is also preferable to add a hindered phenolic antioxidant. As such a hindered phenol-based antioxidant, known ones may be used. For example, pentaerythritol-tetra extract [3- (3,5-di-ter
t-butyl-4-hydroxyphenyl) propionate], 1,1,3-tris (2-methyl-4-hydroxy-
5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, 3,9-bis {2- [3-
(3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl
-2,4,8,10-tetraoxaspiro [4,5] undecane,
1,3,5-tris (4-tert-butyl-3-hydroxy-
2,6-dimethylbenzene) isophthalic acid, triethylglycol-bis [3- (3-tert-butyl-methyl-4)
-Hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3,5-di-tert-butyl-
4-hydroxyphenyl) propionate], 2,2-thio-diethylene-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di- tert-butyl-4-hydroxyphenyl) propionate]. Among them, pentaerythritol-tetra extract [3- (3,5-di-t
ert-butyl-4-hydroxyphenyl) propionate]. In this case, the hindered phenol-based oxidation stabilizer may be bonded to polytrimethylene terephthalate, or may be simply dispersed in the fiber. The amount of the hindered phenol-based oxidation stabilizer is preferably 1% by weight or less based on the weight of the fiber.
If the amount exceeds 1% by weight, coloring may occur, and even if 1% by weight or more is added, the ability to improve the melt stability is saturated. The addition amount of the hindered phenol-based oxidation stabilizer is preferably 0.02 to 0.5% by weight.

Further, in order to improve the whiteness, a whitening agent may be used, and examples thereof include East Bright manufactured by Eastman and Hostaperm pigment described in JP-A-5-262682. The amount of the whitening agent to be used is 0.5 to the weight of the fiber from the viewpoint of the whitening effect and the coloring property of the dyed material.
% By weight or less is preferred.

The method for producing the raw material used in the present invention is not particularly limited, but preferred methods are roughly classified into the following two methods.

The first method uses a lower alcohol diester of terephthalic acid such as dimethyl terephthalate and trimethylene glycol.

That is, a lower alcohol diester of terephthalic acid such as dimethyl terephthalate is reacted with trimethylene glycol at a temperature of 200 to 240 ° C. to effect transesterification, and then at least 1 torr or less, preferably 0.5 torr or less under reduced pressure, 250 to 290 ° C. , Preferably at 260-280 ° C to obtain the desired polymer. Here, the polycondensation reaction temperature is particularly important, and the higher the temperature, the faster the reaction rate, but the easier it is to color. Conversely, polymerization at a temperature lower than 260 ° C. increases the amount of cyclic dimer. Therefore, it is preferable to select the reaction temperature by well balancing the reaction rate and the amount of cyclic dimer. The preferred polycondensation temperature is 260-280 ° C.

The molar ratio of the lower alcohol diester of terephthalic acid and the trimethylene glycol transesterification catalyst at the time of charging is 1: 1.3 to 1: 4, preferably 1: 1.5 to 1: 2.5. 1: 1.
If the amount of trimethylene glycol is less than 3, the reaction time will be extremely long, and the raw material will be colored. When the amount of trimethylene glycol becomes larger than 1: 4, BP
The production amount of E is more than 2% by weight.

It is necessary to use a transesterification catalyst without fail, and preferred examples thereof include calcium acetate, magnesium acetate, zinc acetate, and titanium acetate. The amount of the transesterification catalyst added is preferably 0.02 to 0.1% by weight based on the terephthalic acid diester used. In addition,
Manganese acetate also acts as a transesterification catalyst, but since the amount of cyclic dimer exceeds 3% by weight, when solid-state polymerization is not performed for the purpose of reducing the amount of cyclic dimer produced as described later, manganese acetate is used. The use of should be avoided.

It is necessary to use a polycondensation catalyst without fail, for example,
Titanium alkoxide represented by titanium tetrabutoxide and titanium tetraisopropoxide, antimony acetate, antimony trioxide and the like can be mentioned. Titanium tetrabutoxide is particularly preferred in that the reaction speed is high and the amount of cyclic dimer is small. The addition amount of the polycondensation catalyst is preferably 0.03 to 0.1% by weight based on the terephthalic acid diester used.

According to the first method, the limiting viscosity of the raw material can reach about 0.4 to 0.8. The amount of the cyclic dimer is usually 2 to 3% by weight, and the amount of BPE is 0.2% by weight or less.

The second method uses terephthalic acid and trimethylene glycol.

That is, terephthalic acid and trimethylene glycol
The reaction is carried out at a temperature of from 0 to 240 ° C. to effect transesterification, and thereafter, at a pressure of at least 1 torr or less, preferably 0.5 torr or less, at 250 to 290 ° C., particularly preferably at 260 to 280 ° C. for the same reason as in the first method. The desired raw material is obtained by the condensation reaction. In this case, in order to smoothly carry out the transesterification reaction, 5 to 50% by weight of bis (3-hydroxypropyl) terephthalate, which is a transesterification product, is added at the stage of starting the reaction, and the reaction is uniformly performed. Is also preferable from the viewpoint of increasing the reaction rate.

The molar ratio at the time of charging the terephthalic acid and trimethylene glycol transesterification catalyst is 1: 1.3 to 1: 4, preferably 1: 1.
1.5 to 1: 2.1. If the amount of trimethylene glycol is less than 1: 1.3, the reaction time becomes extremely long and the raw material is colored. On the other hand, if the amount of trimethylene glycol is larger than 1: 4, the amount of BPE produced will be more than 2% by weight.

In the second method, since a proton released from terephthalic acid acts as a transesterification catalyst, a transesterification catalyst is not necessarily required, but it is preferable to use the transesterification catalyst to increase the reaction rate. Preferred examples include, for example,
Examples thereof include titanium alkoxide represented by titanium tetrabutoxide and titanium tetraisopropoxide.
The amount of the transesterification catalyst is preferably 0.02 to 0.1% by weight based on the terephthalic acid used.

It is necessary to use a polycondensation catalyst without fail, for example,
Examples include titanium alkoxide represented by titanium tetrabutoxide and titanium tetraisopropoxide, antimony acetate, antimony trioxide and the like, but titanium tetrabutoxide is particularly preferred in that the reaction speed is high and the amount of cyclic dimer is small. . The amount of the polycondensation catalyst is preferably 0.03 to 0.1% by weight based on the terephthalic acid used.
It is.

The limiting viscosity of the raw material obtained by the second method in this way is 0.
It can reach up to about 4-0.8. The amount of cyclic dimer is usually 2-3% by weight, and the amount of BPE is 0.5-1.0% by weight.
It is. Therefore, in order to enhance the dyeability of the obtained fiber, it is preferable to use terephthalic acid as a raw material.

Incidentally, the phosphorus compound and the cobalt compound used in the present invention, a hindered phenolic antioxidant and a whitening agent,
In any of the above two methods, the compound may be added at any stage of the polymerization, or may be added all at once or in several portions. This is preferable in that coloring can be suppressed most without inhibiting the reaction. If the temperature of the content during the polymerization is higher than the boiling point of the phosphorus compound used, if it is added as it is, it will evaporate and the predetermined amount cannot be added. In such a case, a method of once dissolving in trimethylene glycol at a temperature of at least 50 ° C. or higher, and once reacting with trimethylene glycol to increase the boiling point, and then adding it is particularly preferable. By using such a method, a desired amount of phosphorus element can be provided to the raw material. For cobalt compounds,
Since it can also function as a transesterification catalyst, it is preferably added before the transesterification reaction.

The raw materials obtained by the two methods described above are those necessary for producing the polyester fiber of the present invention,
In these methods, the intrinsic viscosity of the obtained raw materials and fibers is reduced to 0.
It will be difficult to increase to 81 or more. For example, if the reaction temperature is increased to increase the intrinsic viscosity, thermal decomposition may occur and the viscosity may not be increased.

A preferred method for achieving an intrinsic viscosity of 0.81 or more is to use solid-state polymerization. The use of solid-phase polymerization makes it possible to increase the intrinsic viscosity up to 2.0. Solid-state polymerization is a process in which chips, powder, fibrous, plate-like, and block-shaped raw materials are used in the presence of an inert gas such as nitrogen or argon, or
170 to 22 under reduced pressure of 100 torr or less, preferably 10 torr or less
It can be performed at 0 ° C. for about 3 to 48 hours. As an advantage of performing solid phase polymerization, in addition to increasing the intrinsic viscosity, the cyclic dimer has sublimability, so that during the solid phase polymerization, the cyclic dimer escapes from the raw material, so that the cyclic dimer in the resin composition is The amount can be up to 2% by weight, preferably up to 1% by weight. In this case, even if the amount of the cyclic dimer exceeds 3% by weight before the solid phase polymerization, the amount of the cyclic dimer can be reduced to 3% by weight or less after the solid state polymerization.

Therefore, by combining melt polymerization and solid state polymerization,
It becomes possible to produce the most preferable raw materials for producing the polyester fiber of the present invention.

The form of the polyester fiber of the present invention may be any of a long fiber and a short fiber, and in the case of a long fiber, any of a multifilament and a monofilament may be used. Further, the nonwoven fabric may be constituted by using at least a part of the fiber of the present invention. Examples of the nonwoven fabric production method include a spunbond method, a spunlace method, a melt blow method, a flash spinning method, and the like. There is also no particular limitation on the fiber structure, and unstretched yarn obtained by a normal method, drawn yarn obtained by a normal method, straight drawing method, high-speed spinning method, etc., semi-drawn yarn used for false twisting (so-called POY), Any of the structures used in ordinary synthetic fibers, such as various processed yarns, can be included. In addition, there is no particular limitation on the total denier.
When it is used for clothing, it is particularly preferably 5 to 200 d.
Single yarn denier is also not particularly limited, but is preferably 0.0001 to
10d. The cross-sectional shape is round, triangular,
There is no particular limitation on a flat type, a star type, a w type, etc., and it may be solid or hollow.

The polyester fiber of the present invention needs to have a birefringence of 0.03 or more. The birefringence is a parameter indicating the orientation of the polymer chains in the fiber in the fiber axis direction. When the birefringence is less than 0.03, the orientation of the polymer chain of the obtained fiber is insufficient, and the polymer chain exists in a state where it is easy to move, so that the physical properties of the fiber change with time even when stored near normal temperature. I found something. Even if the fibers are made into a fabric in such a state that the structural change is likely to occur, the dyeability and the physical properties of the fabric change in the storage state, so that the fabric is liable to cause stain spots and spots in physical properties. In order to eliminate such a change in the fiber structure, the birefringence of the fiber is preferably 0.05 or more,
More preferably, it is 0.06 to 0.20. Fibers having a birefringence of 0.03 to 0.06 can be twisted or false-twisted while being further stretched to provide a processed yarn having bulky properties and stretch properties.

Hereinafter, the mechanical properties of the polyester fiber of the present invention will be described.

For example, when the polyester fiber of the present invention is a drawn yarn, the strength varies depending on the intrinsic viscosity and the draw ratio, but is usually
3.5g / d or more. In particular, the greatest feature of the present invention with respect to strength is that, since the melt stability of the raw material polymer is sufficiently enhanced, even if the intrinsic viscosity is increased, a decrease in the molecular weight does not easily occur in the melting stage, and the fiber exhibits high strength. It is possible to do that. Therefore, in the polyester fiber of the present invention, for example, if the intrinsic viscosity is about 0.7 and 4 g / d or more, and if the intrinsic viscosity is 1 or more, it is possible to develop a strength of 5 g / d or more, and in some cases, 6 g / d. Become. In this case, the elongation of the fiber is about 25 to 50%.

The elastic modulus is a major feature of the polyester fiber of the present invention, and shows an extremely small value of about 20 to 30 g / d. A small elastic modulus of the fiber leads to a fabric product having an extremely soft texture. Further, the remarkably excellent elastic recovery is a major feature of the polyester fiber of the present invention. Even if the fiber is stretched to about 15%, the polyester fiber of the present invention returns to almost 100% of its original length,
It shows an elastic recovery rate exceeding 80% even at% elongation. Therefore, when the polyester fiber of the present invention is used as a fabric, it is possible to provide a fabric having a soft feel and a good stretch property while having appropriate strength.

The method for producing the polyester fiber of the present invention will be described below using a drawn yarn as an example.

The polyester fiber of the present invention is at least 100 ppm, preferably a raw material dried to a water content of 50 ppm or less is melted using an extruder or the like, and then the molten raw material is extruded from a spinneret, wound up, and then stretched. It can be manufactured by performing. Here, performing drawing after winding means that after spinning, winding is performed on a bobbin or the like, and the yarn is drawn using another device. After being cooled and solidified, it is wound around the first roll rotating at a constant speed several times, so that the tension before and after the roll is not transmitted at all, and installed next to the first roll and the first roll. This is a so-called straight drawing method in which a spinning-drawing process is directly connected, such as drawing between a second roll.

 Hereinafter, the ordinary method will be described with reference to examples.

In the present invention, the spinning temperature when melt spinning the raw material is
240-320 ° C, preferably 240-300 ° C, more preferably 24
A range from 0 to 280 ° C is suitable. When the spinning temperature is lower than 240 ° C., the temperature is too low and it is difficult to obtain a stable molten state, the resulting fiber has large unevenness, and does not exhibit satisfactory strength and elongation. On the other hand, when the spinning temperature exceeds 320 ° C., the thermal decomposition becomes severe, and the obtained yarn is colored and does not show satisfactory strength and elongation.

The winding speed of the yarn is not particularly limited, but is usually 3500 m /
Min or less, preferably 2500 m / min or less, more preferably 2000 m / min.
Take up at m / min or less. If the winding speed exceeds 3500m / min,
Since the crystallization of the fiber proceeds too much before winding, the stretching ratio cannot be increased in the stretching process, so that the molecules cannot be oriented, and the fiber having sufficient yarn strength and elastic recovery cannot be obtained. , The winding of the wound body occurs,
The bobbin or the like cannot be pulled out of the winder.
The stretching ratio during stretching is 2 to 4 times, preferably 2.2 to 3.7.
Times, more preferably 2.2 to 3.1 times. By combining such a stretching treatment and a heat treatment described later, the birefringence of the fiber can be made 0.03 or more. If the draw ratio is less than 2 times, the polymer molecules cannot be sufficiently oriented by drawing, and the elastic recovery of the obtained fiber will be low. On the other hand, if the stretching ratio is 4 or more, thread breakage is severe and stretching cannot be performed stably.

The temperature at the time of stretching is 30 to 80 ° C, preferably 35 to 70 ° C, more preferably 40 to 65 ° C in the stretching zone. If the temperature of the drawing zone is lower than 30 ° C., yarn breakage occurs frequently during drawing, and fibers cannot be obtained continuously. On the other hand, if the temperature exceeds 80 ° C., the slipperiness of the fiber with respect to a heating zone such as a drawing roll deteriorates, so that single yarn breakage occurs frequently and the yarn is full of fluff. Further, since the polymers slip through each other, the fibers are not sufficiently oriented, and the elastic recovery rate of the fibers is reduced.

In order to prevent the fiber structure from changing with time, it is necessary to perform heat treatment after drawing. This heat treatment is performed at a temperature of 90 to 200 ° C, preferably 100 to 190 ° C, and more preferably 110 to 180 ° C. If the heat treatment temperature is lower than 90 ° C., the crystallization of the fiber does not sufficiently occur, and the elastic recovery of the fiber decreases. Also, 20
If the drawing temperature is higher than 0 ° C., the fiber is cut in the heat treatment zone and cannot be drawn.

 Hereinafter, an example of the direct elongation method will be described.

The melted multifilament extruded from the spinneret is provided immediately below the spinneret.
m to suppress rapid cooling after passing through a heat insulation area, rapidly cool this molten multifilament into a solidified multifilament, and heat it to 40-70 ° C with a first roll heated to 300-3 ° C.
Wind at 000m / min, then 120-160 ℃ without winding
Winded around the heated second roll, and stretched 1.5 to 3 times between the first roll and the second roll with a higher speed than the first roll, and then wound using a winder at a lower speed than the second roll. take. A confounding treatment may be performed as necessary in the spinning process. The undrawn yarn once wound at a spinning speed of 300 to 3000 m / min may be wound through the above-mentioned first roll and second roll.

As in the normal method, the polymer is also melt-extruded in the straight-drawing method, and the molten multifilament extruded from the spinneret is not immediately quenched, but is maintained at an ambient temperature of 30 to 200 ° C provided immediately below the spinneret. It is very preferable that the molten multifilament is rapidly cooled after being passed through a heat insulation region of 2 to 80 cm to suppress the rapid cooling and then converted into a solidified multifilament for the subsequent drawing step. By passing through the heat retaining region, the polymer can suppress the generation of fine crystals and extremely oriented amorphous portions in the fiber due to quenching, and can form an amorphous structure that is easily stretched in the stretching step. As a result, the fiber properties required in the present invention can be achieved. Since polytrimethylene terephthalate has, for example, a much higher crystallization rate than polyester such as polyethylene terephthalate, such cooling can be performed by removing fine crystals or extremely oriented amorphous portions. This is an extremely effective method for suppressing the formation of. If the ambient temperature immediately below the spinneret is lower than 30 ° C., rapid cooling occurs, making it difficult to increase the draw ratio. If the ambient temperature is 200 ° C. or higher, yarn breakage tends to occur. Therefore, the temperature of the heat retaining region is preferably from 40 to 200 ° C, more preferably from 50 to 150 ° C. Further, the length of the heat retaining region is preferably 5 to 30 cm.

Regarding the spinning speed of the yarn, the winding speed of the first roll is 300 to 4000 m / min. If the spinning speed is less than 300m / min,
Spinning stability is excellent, but productivity is greatly reduced. Also, if it exceeds 4000 m / min, the orientation or partial crystallization of the amorphous part proceeds before winding, and the stretching ratio of the fiber cannot be increased in the stretching process, so that the molecules cannot be oriented. However, it is difficult for the fiber to exhibit sufficient yarn strength. The spinning speed is preferably between 1500 and 2700 m / min.

It is necessary that the speed of the winder be lower than that of the second roll to cause the orientation relaxation of the amorphous portion of the fiber,
As a result, the large shrinkage of the polytrimethylene terephthalate fiber is reduced, and the amorphous portion is loosened to have a structure in which the dye easily enters, so that the dyeability is slightly improved. The relaxation ratio (winding speed / second roll speed) is 0.95 to 0.5.
It is about 99, preferably 0.95 to 0.98.

The speed of the second roll is determined by the draw ratio, and is usually 600 to 6000 m / min. The stretching ratio between the first roll and the second roll is 1.3 to 3 times, preferably 2 to 2.7 times. By combining such a stretching treatment and a heat treatment described later, the birefringence of the fiber can be made 0.03 or more. If the draw ratio is 1.3 or less, the polymer cannot be sufficiently oriented by drawing, and the strength and elastic recovery of the obtained fiber will be low. When the stretching ratio is 3 times or more, fluff is generated so stably that stretching cannot be performed. The temperature of the first roll is 40 to 70 ° C., and in this range, a state in which stretching is easy can be created. First, the temperature of the roll is preferably 50-60 ° C. Perform heat setting on the second roll, but with a roll temperature of 120
~ 160 ° C. When the second roll temperature is lower than 120 ° C., the fiber becomes poor in thermal stability, is easily deformed by heat and changes with time, and the coloring property in dyeing is reduced. Also, if the second roll temperature is
At 160 ° C. or higher, fluff or yarn breakage occurs, and stable spinning cannot be performed. The temperature of the second roll is preferably 120 to 1
50 ° C.

The polyester fiber obtained as described above can be used alone or by using a part of a fabric to provide softness,
The resulting fabric has excellent stretchability and coloring properties in dyeing. There is no particular limitation on other fibers when used for a part of the fabric, but in particular, by mixing with fibers such as stretch fibers such as polyurethane elastic fibers, cellulose fibers, wool, silk, and acetate fibers, known fibers are used. It is possible to exhibit characteristics such as softness and stretchability that cannot be obtained with a mixed fabric using synthetic fibers or chemical fibers.

In the present invention, a fabric refers to a woven or knitted fabric. The fabric of the present invention, including the above-mentioned mixed fabric, is not particularly limited in the form of the polyester fiber to be used and the knitting and weaving method, and known methods can be used. For example, a plain woven fabric used for a warp or a weft, a woven fabric such as a reversible woven fabric, a knitted fabric such as tricot and Russell, and the like may be used.

The fabric of the present invention, including mixed fabrics, may be dyed. For example, after knitting and weaving, scouring, pre-setting,
It can be dyed through the process of dyeing and final setting. If necessary, after scouring and before dyeing, alkali reduction treatment can be carried out by a conventional method.

Refining can be performed in a temperature range of 40-98 ° C. In particular, in the case of mixing with stretch fibers, scouring while relaxing is more preferable because the elasticity is improved.

It is possible to omit one or both of the heat setting before and after dyeing, but it is preferable to perform both heat setting in order to improve the form stability and dyeability of the fabric. The temperature of the heat setting is 120 to 210 ° C., preferably 140 to 180 ° C., and the heat setting time is 10 seconds to 5 minutes, preferably,
20 seconds to 3 minutes.

Dyeing can be carried out without using a carrier at a temperature of 70 to 150 ° C, preferably 90 to 120 ° C, particularly preferably 90 to 100 ° C. In order to carry out level dyeing, it is particularly preferable to adjust the pH according to the dye using acetic acid, sodium hydroxide, or the like, and to use a dispersant composed of a surfactant.

After dyeing, the fabric is subjected to soaping or reduction cleaning by a known method. These methods may be known methods. For example, the treatment can be performed in an aqueous alkali solution such as sodium carbonate or sodium hydroxide using a reducing agent such as sodium hydrosulfite.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail with reference to examples. However, needless to say, the present invention is not limited to the examples. The main measured values in the examples were measured by the following methods.

(1) Measurement of intrinsic viscosity of raw material and fiber The intrinsic viscosity [η] was measured using an Ostwald viscometer,
° C, specific viscosity ηsp and concentration C using o-chlorophenol
The ratio ηsp / C of (g / 100 ml) was extrapolated to zero concentration and determined according to the following equation.

(2) Phosphorus element amount, cobalt element amount in raw material and fiber,
Measurement of the amount of metal element used as polycondensation catalyst and X value The amount of metal element used as polycondensation catalyst such as phosphorus element, cobalt element and titanium is determined by high frequency plasma emission spectroscopy (model: IRIS-AP, Thermojarrel Ash) Company)
It measured using. The analysis sample was prepared as follows. 0.5 g of the sample and 15 ml of concentrated sulfuric acid were added to an Erlenmeyer flask, and the mixture was decomposed for 3 hours on a hot plate at 150 ° C. and 2 hours on a hot plate at 350 ° C. After cooling, 5 ml of aqueous hydrogen peroxide was added to oxidize and decompose. The solution was concentrated to 5 ml, 5 ml of an aqueous solution of concentrated hydrochloric acid / water (1: 1) was added, and 40 ml of water was further added. An analysis sample was used. The X value indicates the ratio of the number of moles of the phosphorus element of the phosphorus compound to the number of moles of the metal element used as the polycondensation catalyst (= the number of moles of the phosphorus element of the phosphorus compound / the number of moles of the metal element used as the polycondensation catalyst).

(3) Measurement of coloring degree (yellowishness) of raw materials and fibers In the case of finely divided raw materials or fibers, six-layered one-piece knitted fabric (28G, India) is used and a color computer (manufactured by Suga Test Instruments Co., Ltd.) is used. And colorimetry. The b value indicates yellowness and bluishness, and the yellowness increases as the numerical value increases from 0. Conversely, the bluishness increases as the numerical value decreases from 0. The closer to 0, the more colorless.

(4) Measurement of melting points of raw materials and fibers Using a DSC manufactured by Seiko Denshi Co.,
The measurement was performed under a nitrogen stream of 00 ml / min. Here, the peak value of the melting peak was defined as the melting point.

(5) Measurement of the amount of the cyclic dimer in the raw material and the fiber 0.3 g of the resin composition or the fiber was weighed, added to a mixture of 5 ml of hexafluoroisopropanol and 5 ml of chloroform, and dissolved at room temperature. After complete dissolution, add 5 ml of chloroform and add about 80
Milliliter of acetonitrile was added. At this time, insolubles precipitated, but were separated by filtration, and the filtrate was all transferred to a 300 ml flask and acetonitrile was added to obtain a transparent solution having a total amount of 200 ml.

This solution was analyzed using high performance liquid chromatography, and the amount of cyclic dimer was measured. Column is μBond asph
ere 15 μC-18-100A 3.9 × 190 mm (manufactured by Waters) was used, water / acetonitrile (volume ratio 30/70) was used as a mobile phase, and ultraviolet light having a wavelength of 242 nm was used as a detector. The temperature was 45 ° C. and the flow rate was 1.5 ml / min.

(6) Measurement of BPE in raw material and fiber 2 g of finely divided raw material or fiber is added to 25 ml of 2N potassium hydroxide in methanol solution, and solvolysis is carried out under reflux for 4 hours. And quantified by gas chromatography. Column is DURABOND
Helium 1 using DB-WA x 0.25mm x 30m (0.25μm)
20 from 150 to 230 ° C while flowing 00 ml / min
It was measured at a heating rate of ° C./min.

(7) Spinning method and measurement of fluff rate After the raw material is dried, it is melted at an extrusion temperature of 270 ° C., melted and spun at a spinning speed of 1500 m / min through a spinneret (36 holes, 0.23 mm), and an undrawn yarn Was wound up. Next, the undrawn yarn was passed through a hot roll at 55 ° C. and a hot plate at 140 ° C., and drawn 2.4 times. The fineness and the number of filaments of the obtained fiber were set to 50d / 36f. The fluff rate was 1000 pieces of 500 g burn, and the number of fluff on the surface was counted, and the number obtained by dividing the number by 1000 was multiplied by 100 to obtain the fluff rate.

(8) Measurement of Retention Rate of Melt Viscosity of Raw Material The numerical value obtained by dividing the intrinsic viscosity of the raw material obtained by the method of (7) by the intrinsic viscosity of the raw material and multiplying by 100 to obtain the melt viscosity retention rate. .

(9) Measurement of Mechanical Properties of Fiber (Strength, Elongation, Elasticity) Various mechanical properties of fiber were measured according to JIS-L-1013.

(10) Measurement of elastic recovery The fiber was attached to a tensile tester at a distance between chucks of 20 cm, stretched at a stretching speed of 20 cm / min to an elongation of 20%, and allowed to stand for 1 minute. After that, it is contracted again at the same speed,
Draw a distortion curve. The elongation when the stress becomes zero during shrinkage is defined as residual elongation (A). The elastic recovery was determined according to the following equation.

Elastic recovery rate = (20−A) / 20 × 100 (%) (11) Measurement of birefringence Textile Handbook / Raw material-P969 (5th press [1978] Maruzen Co., Ltd.) Using an optical microscope and a compensator From the retardation observed on the surface of the fiber.

Example 1 Dimethyl terephthalate (hereinafter abbreviated as DMT) 25000
To a mixture of 2553 parts by weight of trimethylene glycol and 21553 parts by weight of trimethylene glycol, a 7: 1 mixture of calcium acetate and cobalt acetate tetrahydrate was added in an amount of 0.1% by weight / DMT (this unit represents a weight ratio to DMT). Transesterification was performed at 240 ° C. for 4 hours. Next, titanium tetrabutoxide was added at 0.1% by weight / DM.
T, 0.05% by weight of trimethyl phosphate / DMT, 2
Polycondensation was performed at 70 ° C. and 0.2 torr for 3 hours. The obtained resin composition was a resin composition containing 97% by weight of polytrimethylene terephthalate. Table 1 shows the physical properties of the obtained resin composition.
Table 2 shows the physical properties of the obtained fiber. The fiber obtained by melt-spinning this resin composition was excellent in whiteness, low in fuzz, and had a small decrease in viscosity at the spinning stage.

Examples 2 and 3 Example 1 was repeated, except that the amounts of cobalt acetate and trimethyl phosphate were changed. The obtained resin composition was a resin composition containing 97% by weight of polytrimethylene terephthalate. Table 1 shows physical properties of the obtained resin composition, and Table 2 shows physical properties of the obtained fiber.

The fiber obtained using this resin composition had excellent whiteness, low fuzz rate, and small decrease in viscosity during the spinning step.

Example 4 As a transesterification catalyst, a 7: 1 mixture of calcium acetate and cobalt acetate tetrahydrate was used in an amount of 0.1% by weight of the theoretical polymer.
In addition, the same experiment as in Example 1 was performed except that the polymerization temperature was 250 ° C. and the polymerization time was 2 hours. The obtained resin composition was a resin composition containing 97% by weight of polytrimethylene terephthalate. Table 1 shows physical properties of the obtained resin composition, and Table 2 shows physical properties of the obtained fiber.

As a result of melt spinning of this resin composition, a yarn having excellent whiteness and a low fuzz rate was obtained. The decrease in viscosity during the spinning stage was small.

Example 5 1300 parts by weight of terephthalic acid (hereinafter abbreviated as TPA),
1369 parts by weight of trimethylene glycol, cobalt acetate 0.01
Weight% / TPA slurry under normal pressure, heater temperature 240 ℃
Was transesterified. Next, titanium tetrabutoxide
0.1% by weight / DMT, 0.05% by weight of trimethyl phosphate /
TPA was added and polycondensation was performed at 270 ° C. and 0.2 torr for 3 hours. The obtained resin composition is obtained by mixing polytrimethylene terephthalate.
The resin composition contained 97% by weight.

Table 1 shows physical properties of the obtained resin composition, and Table 2 shows physical properties of the obtained fiber.

As a result of melt-spinning the resin composition, fibers having excellent whiteness were obtained, the spinning stability was low and the fuzz rate was low, and the viscosity decrease in the spinning stage was small.

Example 6 Example 5 was repeated, except that cobalt carbonate was used instead of cobalt acetate tetrahydrate and tributyl phosphate was used instead of trimethyl phosphate, and the amount of addition was changed. The obtained resin composition was obtained by mixing polytrimethylene terephthalate with 97
It was a resin composition containing by weight. Table 1 shows physical properties of the obtained resin composition, and Table 2 shows physical properties of the obtained fiber.

The fiber obtained by spinning this resin composition was excellent in whiteness, low in fuzz, and small in viscosity decrease in the spinning stage.

Example 7 Example 5 was repeated using tributyl phosphite instead of trimethyl phosphate and no cobalt acetate. The obtained polymer was a resin composition containing 97% by weight of polytrimethylene terephthalate.

Table 1 shows physical properties of the obtained resin composition, and Table 2 shows physical properties of the obtained fiber.

The fiber obtained using this resin composition had excellent whiteness, low fuzz rate, and small decrease in viscosity during the spinning step.

Example 8 The resin composition of Example 1 was subjected to solid-state polymerization at 215 ° C. for 5 hours under a nitrogen stream. The obtained resin composition was a resin composition containing 98% by weight of polytrimethylene terephthalate, and the cyclic dimer amount was greatly reduced to 0.9%. Further, the strength of the fiber was increased, reflecting the increase in the viscosity.

REFERENCE EXAMPLE 1 One-port knitted fabric (28G, sheeting) of the fiber obtained in
Heat set at ℃ for 30 seconds, then Dianix Black
HG-FS (Dystar Japan, disperse dye) 4% owf
The dyeing was carried out at 98 ° C. for 1 hour at pH 5 in the presence of 1 g / liter of Disper TL (manufactured by Meisei Chemical Co., Ltd.) at a bath ratio of 1:30.

The dye exhaustion was 53%, and the dyed product was placed in a fade meter at 63 ° C. for 27 hours and examined for light fastness. No fading was observed. On the other hand, when a similar experiment was carried out using the fiber obtained in Example 6, the dye exhaustion was 84%, and no fading was observed in the light fastness test.

Comparative Example 1 Titanium tetrabutoxide 0.1 as transesterification catalyst
Example 1 was repeated using 0.1% by weight / DMT as the transesterification catalyst and 0.1% by weight / DMT titanium tetrabutoxide without using trimethyl phosphite and cobalt acetate. The obtained resin composition was a resin composition containing 97% by weight of polytrimethylene terephthalate.
Further, only a yarn having low strength was obtained due to low melt stability.

Comparative Example 2 Example 1 was repeated without lowering the polycondensation temperature to 250 ° C and using trimethyl phosphite and cobalt acetate.
Although the obtained resin composition was a resin composition containing 95% by weight of polytrimethylene terephthalate, it was markedly colored. In addition, only low strength yarn was obtained due to low melt stability. Furthermore, the amount of cyclic dimer is 3% by weight.
And the fluff rate increased.

Comparative Example 3 The resin composition obtained in Comparative Example 1 was subjected to
Solid-state polymerization was performed at 5 ° C. for 5 hours to obtain a resin composition having an intrinsic viscosity of 1.1. This resin composition was a resin composition containing 97% by weight of polytrimethylene terephthalate.

When spinning was performed using this resin composition, the viscosity retention decreased to 64%, and only mechanical properties with a strength of 3.5 g / d and an elongation of 35% were exhibited.

Comparative Example 4 An experiment was performed in the same manner as in Example 1 except that the use amount of trimethylene glycol was increased eight-fold. Of the obtained resin composition
The BPE amount was 2.1% by weight. This resin composition was a resin composition containing 96% by weight of polytrimethylene terephthalate.

The resin composition was fiberized, dyed in the same manner as in Reference Example 1, and subjected to a light resistance test with a fade meter. As a result, fading of the dyed product was observed. On the other hand, no fading was observed in the dyed product of the fiber of Example 1.

Comparative Example 5 A slurry of 1300 parts by weight of TPA, 1369 parts by weight of trimethylene glycol, and 0.01% by weight of cobalt acetate / TPA was transesterified at a heater temperature of 240 ° C. under normal pressure. Next, 0.1 wt% butylstannic acid / DMT and tridecyl phosphite
0.05% by weight / TPA was added, and polycondensation was performed at 270 ° C. and 0.2 torr for 3 hours. The b value of the obtained resin composition was 14 and colored yellow, and the amount of cyclic dimer was 3.4% by weight. This resin composition contains 96% by weight of polytrimethylene terephthalate.
It was a resin composition containing:

Fibers obtained using this resin composition were colored yellow and had a high fuzz ratio of 0.9 due to a large amount of cyclic dimers.

Example 9 After the transesterification reaction was completed, pentaerythritol-tetra extract [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (Irganox 10
10, 0.07% by weight of Ciba Specialty Chemical Co.)
Example 6 was repeated except that / TPA was added. This resin composition was a resin composition containing 96% by weight of polytrimethylene terephthalate. The viscosity retention of this polymer is 98
%. Cut this resin composition into 3mm square, 1
The resulting acrolein and allyl alcohol were captured in a dry ice-methanol bath by heating at 30 ° C. for 6 hours in air. The amount of acrolein and allyl alcohol produced at this time was 0.15 mg, 0.2 g per 1 g of the resin composition of 1 g, respectively.
It was 0 mg. In contrast, the amounts of acrolein and allyl alcohol produced in the resin composition of Example 1 were 0.51 mg each,
0.82 mg.

Example 10 The fiber obtained in Example 1 was cut and cut to 39 mm. Example 2
A 20d / 2f filament obtained in the same manner as described above was used as a core, and a short yarn was arranged in a sheath to obtain a composite yarn having a filament mixing ratio of 11% by weight. The composite yarn is warp (weaving density 146 yarns / 25.4m
m) and a weft (woven density: 77 yarns / 25.4 mm), woven into a plain woven fabric, and dyed at 95 ° C. by the same dyeing method as in Reference Example 1.

The obtained fabric was dyed in a dark color and had excellent color developability. Further, the obtained fabric was soft, had a light stretch property, and was excellent in tension, waist, and resilience.

Example 11 A plain woven fabric was prepared using 75d / 36f polyester fiber obtained in the same manner as in Example 1 for warp and weft. This plain fabric was scoured by a conventional method, and then, after presetting at 180 ° C. for 30 seconds, dyeing was performed using a disperse dye without using a carrier. As a disperse dye, Kayaron Polyester Blue 3RSF (manufactured by Nippon Kayaku Co., Ltd.) 5% owf was used, and as a dispersant, 1 g / liter of Disper TL (manufactured by Meisei Chemical Co., Ltd.) was used. Dyeing was performed at 110 ° C. for 1 hour at a bath ratio of 1:50. After dyeing, soaping was performed at 80 ° C. for 10 minutes at 1 g / liter of Gran Up P (manufactured by Sanyo Chemical Industries, nonionic surfactant) at a bath ratio of 1:50. After dyeing, finishing was performed by a conventional method.

The obtained dyed product was uniformly dyed, and was a soft and good-textured dyed fabric not seen in the conventional art.

Example 12 Using the polyester fiber of Example 1 and 210 denier polyurethane stretch fiber Loica (manufactured by Asahi Kasei Kogyo Co., Ltd.), a warp knitted fabric having a sheet-in-woven structure was knitted at 28G. The loop length of this warp knitted fabric was set to 1080 mm / 480 course for polyester fiber and 112 mm / 480 course for stretch fiber, the driving density was set to 90 course / 25.4, and the mixing ratio of polyester fiber was set to 75.5%.

The obtained greige was relaxed and scoured at 90 ° C for 2 minutes.
A dry heat setting was performed at 1 ° C for 1 minute. Dianix Black BG-FS (Disperse dye manufactured by Dystar Japan) 8% ow
f, Nikkasan Salt 1200 as a dyeing aid was adjusted to pH 6 with acetic acid in the presence of 0.5 g / liter, and the bath ratio was adjusted to 95 at 1:30.
Staining was performed at 60 ° C. for 60 minutes.

The obtained dyed knitted fabric was soft, rich in stretch feeling, excellent in color development, stretched, and had a firm texture.

Comparative Example 6 The resin composition obtained in Example 1 was extruded at 270 ° C., and passed through a spinneret having 36 holes of 0.23 mm, and as it was, 1600 m / min.
Rolled up. Thereafter, heat treatment was performed at 40 ° C. to obtain a 75d / 36f fiber. The birefringence of the obtained fiber was 0.024. When 5 kg of the obtained fiber was wound up and stored in a warehouse, the yarn changed over time and shrunk. When one-piece knitted fabric (28G, India) knitted using this yarn was dyed, a severely shrinking portion was left as stained spots.

Example 13 The resin composition obtained in Example 1 was extruded at 270 ° C. and wound up at 3500 m / min through a 36-hole, 0.23 mm spinneret. The birefringence of the obtained 50d / 36f fiber (POY) is 0.05
It was eight. The obtained fiber did not change with time even when stored in a warehouse. The obtained fiber was stretched 1.4 times while being heated at 160 ° C., and was subjected to false twisting under normal stretching false twisting conditions of 3500 T / m. The obtained false twisted yarn was excellent in stretchability and bulkiness.

Comparative Example 7 Instead of using 0.05% by weight of trimethyl phosphate,
Example 1 was repeated using 0.05% by weight of tris (2,4-di-t-butylphenyl) phosphite.

The resulting resin composition has an intrinsic viscosity of 0.74, contains 96% by weight of polytrimethylene terephthalate, and has a phosphorus element amount of
5 ppm, the amount of cyclic dimer was 3.1% by weight, and the amount of BPE was 0.07% by weight.

When spun using this resin composition, the viscosity retention was 84%, the strength was 3.8 g / d, and the elongation was 33%. Also,
The amount of phosphorus element in the fiber is 4 ppm, and the amount of cyclic dimer is 3.
2% by weight, the amount of BPE was 0.09% by weight.

INDUSTRIAL APPLICABILITY The polyester fiber of the present invention is a polyester fiber excellent in whiteness, spinning stability and polytrimethylene terephthalate resin composition excellent in melt stability, excellent in strength and high in melt stability. The polytrimethylene terephthalate resin composition, which hardly causes a decrease in the degree of polymerization and the degree of polymerization in the spinning stage, can be melt-spun to be industrially advantageously produced.

The polytrimethylene terephthalate fiber of the present invention has good workability and is suitable for clothing products represented by innerwear, outerwear, sportswear, swimwear, panty king, lining, etc. and materials such as carpets, interlining, flocky and the like. In a product, a fabric such as a knitted fabric or the like having a function that cannot be obtained with a general-purpose polyester fiber or nylon fiber can be produced.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-5-262628 (JP, A) JP-A-8-311177 (JP, A) International publication 99/11709 (WO, A1) US patent 5798433 (US, A) TRAUB HL (3 others) "SYT HESIS AND PROPERTIES OF FIBER-GRADE POLY" (Int.Cl. ⁷ , DB name) D01F 6/62 301-308 D01F 6/84 301-311 D01F 6/92 301-309 C08L 67/00-67/08 C08G 63/00-63/91 D03D 15 / 00

Claims (9)

(57) [Claims] 1. A polyester fiber satisfying the following conditions (1) to (5) and having an intrinsic viscosity of 0.4 to 2. (1) 90% by weight or more of polytrimethylene terephthalate is composed of polytrimethylene terephthalate. (3) containing 3% by weight or less of cyclic dimer (4) 2% by weight or less of bis (3-hydroxypropyl)
It contains ether and is copolymerized with polytrimethylene terephthalate. (5) The birefringence is 0.03 or more. 2. The ratio of the number of moles of a phosphorus element of a phosphorus compound to the number of moles of a metal element used as a polycondensation catalyst is as follows:
The polyester fiber according to claim 1, wherein the polyester fiber is 0.4 to 3. 3. The method according to claim 1, wherein the phosphorus compound is O = P (OR ₁ ) (OR ₂ ) (OR
₃ ) phosphate or P (OR ₄ ) (OR ₅ ) (OR ₆ )
The polyester fiber according to claim 1, which is a phosphite. (Here, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , and R ₆ are different or the same, and are selected from a hydrogen atom, an organic group having 1 to 8 carbon atoms, an alkali metal, an alkaline earth metal, It was chosen.) 4. The polyester fiber according to claim 1, further comprising a cobalt compound corresponding to a cobalt element amount of 5 to 200 ppm. 5. The method according to claim 1, wherein the cobalt compound is cobalt acetate, cobalt formate, cobalt carbonate, cobalt acetylacetonate.
The polyester fiber according to claim 4, wherein the polyester fiber is at least one selected from cobalt sulfate. 6. The polyester fiber according to claim 1, wherein the copolymerized bis (3-hydroxypropyl) ether is 0.4 to 1% by weight. 7. The polyester fiber according to claim 1, which contains 1% by weight or less of a hindered phenolic antioxidant. 8. The method according to claim 1, wherein the intrinsic viscosity is 0.81 to 2 and the amount of cyclic dimer is 2% by weight or less.
Polyester fiber as described. 9. A fabric using the polyester fibers according to claim 1 in whole or in part.